Filler injection usually isn’t a single toggle; it’s handled through your agent’s prompt + interruption/latency handling settings (and sometimes via response streaming behavior).
You basically need to instruct the model to use natural hesitations (like uh, hmm) and ensure your TTS/streaming setup isn’t stripping them out.
I can help you set it up properly depending on your current flow (Vapi config + model + voice provider).
@FJ